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Fault-tolerant flocking control against multiple malicious agents under geometric configuration containment

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Science china(Information Sciences) 2024年第10期67卷 261-282页

作者： Chencheng {2. Hao yang Bin JIANG College of Automation Engineering Nanjing University of Aeronautics and Astronautics Institute of Engineering and Technology (ENTEG) University of Groningen

Flocking control in the presence of malicious decisions is a crucial research topic since agents in swarms are likely to suffer from security issues in practice. This paper considers a swarm containing malicious agents that deliberately alter their controller parameters and disrupt the swarm by causing collisions,divisions, and escapes. Two possible malicious scenarios are considered. The first is that one malicious agent acts selectively on a subset of its neighbors and the second is that multiple malicious agents are either scattered or clustered together. To achieve the flocking control objective:(1) containment conditions based on specific geometric configurations are established;(2. hierarchical fault-tolerant flocking control methods based on those containment conditions are proposed. Compared to existing research dealing with malicious agents in swarms, our approach aims to contain rather than remove them. This guarantees the completeness of the task and takes agents' motions into consideration. Simulations show the effectiveness of the proposed methods.

关键词： flocking control fault-tolerant control multiple malicious agents geometric configuration

Constrained Bézier curves' best multi-degree reduction in the L2.norm

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Progress in Natural Science:Materials International 2005年第9期15卷 843-850页

作者： zhang Renjiang 1,2.** and WANG Guojin1(1. Institute of Computer Images and Graphics, Zhejiang {2., Hangzhou 31002., china 2. china Institute of Metrology, Zhejiang, Hangzhou 310034, china) Institute of Computer Images and Graphics Zhejiang University Hangzhou 310027 China. State Key Laboratory of CAD&CG Zhejiang University Hangzhou 310027 China. china Institute of Metrology Zhejiang Hangzhou 310034 China

In computer aided geometric design, the degree reduction of the parameter curve is a key technique in data exchange and data compression. The various existing methods of degree reduction cannot decide whether the degree reduction curve satisfying the given tolerance exists beforehand, cannot give approximation of the best multi-degree reduction, or cannot provide explicit expression and error formula of the degree reduction curve. In this paper, we propose an entirely new method, which can hurdle the above flaws completely. For a given Bézier curve of degree n, we can easily decide whether a Bézier reduction curve of degree m exists, which has equal derivatives with the given curve up to （r-1）-th and （s-1）-th orders （r,s≤m） respectively at the endpoints, so the approximating error is less than the given tolerance ε in the L2.norm. If the curve exists, the explicit expression can be given.

关键词： computer aided design Bézier curve degree reduction L2.norm tolerance.

Indoor imitation experimental study on driving factors of rainfall-runoff process

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Science china earth Sciences 2005年第3期48卷 417-428页

作者： zhang Shifeng1, LIU Changming 1, XIA Jun1, TAN Ge 1, LI Lin1, LIU Caitang1, ZHOU Changqing 1 & GUO Lei2.1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101,{2. 2. College of Water Resources and Hydropower Engineering, wuhan university, wuhan 430072.{2. 1. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. College of Water Resources and Hydropower Engineering Wuhan University 430072 Wuhan China

The driving actions of rainfall-runoff process can be attributed to two aspects. The first is the influence of precipitation process, and the second is that of the ground pad. The re- search results of 179 indoor experiments conducted to imitate rainfall-runoff process indicate that both precipitation duration and intensity play important roles in affecting confluence lag time, which is obviously inconsistent with the traditional hypotheses. The nonlinear relationship is of great significance to the confluence curve especially when the precipitation duration is less than the total confluence time or the precipitation intensity is small. Therefore it can be concluded that the unit hydrograph (UH) can be applied to rainfall-runoff process imitation in the humid areas in the south china region. However, the UH application should be strictly modified in accordance with precipitation conditions in the arid and semiarid region of north china where the precipitation duration is short and the intensity is unstable. It will be hard to get ideal imitation results if the UH is applied blindly without considering specific conditions in the north china region. This also explains the unsatisfactory imitation results caused by using various hydrological models in the north china region. When the precipitation duration is short, and the watershed has not reached total watershed concentration, the characteristics of confluence change greatly, which reflects the actual situation in the north china region. Therefore necessary nonlinear corrections should be made when UH is applied. If the duration is longer than the total confluence time and the balance between pondage and discharge is stricken, the imitation research results will be applicable to both rainfall-runoff relation with longer duration in the south china region and the basic theoreti- cal research on runoff generation and concentration. On conditions of adequate rainfall, peak discharge is in linear relationship with inten

关键词： rainfall-runoff, driving factors, indoor imitation, experiment.

Principle and Technique of Calculating Seismic Velocities from Lattice Preferred Orientation (LPO) Data of Minerals

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Journal of earth Science 1998年第2期17卷 60-66页

作者： Guan Xiaoping Department of Applied Geophysics, china university of geosciences, wuhan 4.0074 Jin Shuyan {2. of earth Sciences, china university of geosciences, wuhan 4.0074

Deducing seismic velocity anisotropy from LPO (lattice preferred orientation) data of deformed rock samples, a significant link between geology and seismology in geoscience researches, has extensive and promising application. In this paper, the principle and programming technique are highlighted to illustrate the comprehensive automatization procedure. In computer algorithm, two aspects of the programs commonly used in the world are improved: (1) the addition of a pre processing subroutine makes the straightforward calculation realizable from universal stage readings to geographic azimuths and thus to solution of all crystal axes, even for non orthorhombic a and c axes in monoclinic systems. (2. the simplification and perfection of programming can be implemented in the light of Visual Basic (VB) resource. The algorithm has been verified with results from practical data of omphacite samples.

关键词： omphacite fabric seismic velocity anisotropy contouring.

Prospects of sediment deposition at small watershed scale in the black soil region of Northeast china: A mini review

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Pedosphere 2024年第1期34卷 30-35页

作者： Guanghui zhang yang yang Yingna LIU Zhiqiang WANG State Key Laboratory of earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of Geography Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Sediment deposition is one of the most significant processes in small watersheds characterized by gentle long hillslopes in the black soil(Mollisol)region of Northeast china, as indicated by severe ephemeral gully and gully erosion on hillslopes and very low sediment concentrations in river *** reviews have been conducted to summarize the related research in this region. The objectives of this review were to identify the potential factors influencing sediment deposition, review related studies, and propose future research needs in the black soil region of Northeast china. Sediment deposition is controlled by the deficit between sediment transport capacity of flow and sediment load. hence, all factors affecting flow transport capacity and sediment load directly affect sediment deposition. For a specific small watershed, the change in slope gradient along the flow path is the key factor affecting sediment deposition. Shelterbelts, ridge tillage systems, terraces, grass strips, road distribution, ponds and reservoirs, and land-use patterns also influence the spatial distribution and rate of deposition. The trace method has been widely used to quantify sediment deposition in this region. The results of cesium-137(^(137)Cs),lead-2.0(^(2.0)Pb), and magnetic susceptibility reveal that serious deposition occurs on the back and foot slopes. Distinct deposition occurs in front of contour shelterbelts. Future studies should focus on the methodology, spatial and temporal variations, dominant influencing factors and their mechanisms, and the potential effects on land productivity within specific small watersheds and across the black soil region. This review provides insights into the sediment deposition process in small watersheds characterized by gentle, long hillslopes.

关键词： Mollisol sedimentation soil and water conservation soil erosion soil redistribution

^(40)Ar-^(39)Ar and U-Pb ages of metadiorite from the East Kunlun Orogenic Belt: Evidence for Early-Paleozoic magmatic zone and excess argon in amphibole minerals

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Chinese Science Bulletin 2001年第4期46卷 330-333页

作者： CheN Nengsong, SUN Min, zhang Kexin & ZHU Yunhai{2. of earth Sciences, china university of geosciences, wuhan 4.0074, china Department of earth Sciences, The university of Hong Kong, Hong Kong SAR, china faculty of earth Sciences China University of Geosciences Wuhan China Department of earth Sciences The University of Hong Kong Hong Kong SAR China

Single-grain zircon U-Pb and amphibole 40Ar-39Ar dating have been conducted on a deformed and metamorphosed diorite in the East Kunlun Orogenic Belt, which intruded into the middle Proterozoic Kuhai Group exposed in the south of Xiangride region, Dulan County, NW Qinghai Province. The zircon gives a concordant U-Pb age of (446.5±9.1) Ma. The amphibole yields Ar plateau age of (488.0±1.2. Ma and an isochronal age of (488.9±5.6) Ma. Age results of both stepwise released Ar and conventional K-Ar analysis are remarkably higher than that of zircon U-Pb, suggesting that the amphibole contains excess argon and the amphibole plateau age cannot be taken as the timing of metamorphism or deformation. The zircon age is interpreted to be crystallization age of the diorite pluton, which suggests that an Early-Paleozoic magmatic zone indeed existed in the East Kunlun Orogenic Belt stretching along the region south to the Golmud, Normuhong and Xiangride.

关键词： East Kunlun Orogenic Belt metadiorite geochronology excess argon.

Mass and Energy Transportation in Ore-Forming Processes of Sulfide Deposits in Tongling District

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Journal of earth Science 1999年第4期18卷 299-304页

作者： Cen Kuang Yu Chongwen(faculty of earth Sciences,{2., wuhan 4.0074) faculty of earth Sciences China University of GeosciencesWuhan 430074

Based on dynamics of heat conduction, fluid flow caused by heating and chemical material transport induced by fluid flow, temperature and stream fields of fluid flow in ore-forming processes of Cu-Au sulfide in the Tongling district deposits was modeled and analyzed. It is shown that: (1) Mass and energy flow caused by fluid flow is key problem of kythrothermal ore-forming processes; the heating from magma intruded is basic power for driving fluid flow. (2. occurrence of pluton, different chemical property and porosity of wall rocks and infiltration restrict the specifically field of precipitation for ore-forming ***, the dissolution and precipitation field for ore-forming material in deposit can be forecasted. (3) Iron and sulfur material comes mostly from sandstone formation of Wutong Group, which contains pyrite and high porosity. The cataclastic dolomite interlayered in sandstone and limestone is a favorable place for ore accumulating. The difference of chemical property between sandstone and dolomite forms a favorable interface for ore-forming processes.

关键词： heat conduction mass transportation fluid path-line streamline

Photocatalytic Degradation of Rhodamine B Dye with High Purity Anatase Nano-TiO_2.Synthesized by a Hydrothermal Method

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Journal of wuhan university of Technology(Materials Science) 2011年第4期26卷 600-605页

作者：史晓亮 School of Mechanical and Electronic Engineering Wuhan University of Technology State Key Laboratory of Advanced Technology for Materials Synthesis & Processing Wuhan University of Technology

High purity anatase nano-TiO2.powders with high photocatalytic activity were prepared by a hydrothermal synthesis method. X-ray diffraction （XRD）, field emission transmission electron microscopy （FETEM）, ultraviolet-visible （UV-Vis） light absorption spectrum and photoluminescence （PL） spectrum were adopted to characterize the catalyst. Effects of temperature, time and sol concentration of hydrothermal synthesis on particle size and phases were investigated. Photocatalytic activities in the degradation of Rhodamine B Dye were studied. The experimental results indicated that photocatalytic activity of the nano-TiO2.powers was much higher than that of P2. （Degussa）.

关键词： TiO2 hydrothermal synthesis photocatalytic activity high purity anatase

A bifunctional POM-based Cu-viologen complex with mixed octamolybdate clusters for rapid oxidation desulfurization and effective photogeneration of hydrogen

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Rare Metals 2024年第1期43卷 236-246页

作者： Lin yang Zhong zhang Chao-Nan zhang Xiu-Li Wang College of Chemistry and Materials Engineering Bohai UniversityJinzhou 121013China Professional Technology Innovation Center of Liaoning Province for Conversion Materials of Solar Cell Bohai UniversityJinzhou 121013China

The design and synthesis of catalysts for the oxidation desulfurization and production of hydrogen are extremely important for solving environmental pollution and energy ***,a novel bifunctional [α-Mo_(8)O_(2.)]^(4-)/[β-Mo_(8)O_(2.)]^(4-)-based Cu-viologen complex H_(4)[Cu_(2.~ⅠCl_(2.(Hbcbpy)_(4)] [α-Mo_(8)O_(2.)] [β-Mo8O_(2.)]·H_(2.O(BHU-2.Hbcbpy=1-(4-carboxybenzyl)-4,4'-bipyridinium) was synthesized and characterized by single-crystal X-ray diffraction(XRD),infrared radiation spectra,powder X-ray diffraction(PXRD) and X-ray photoelectron spectroscopy(XPS) *** structural characteristic of BHU-2.is the presence of two types of octamolybdate clusters [α-Mo_(8)O_(2.)]^(4-)/[β-Mo_(8)O_(2.)]^(4-)and a new binuclear Cu~Ⅰ-Hbcbpy complex linked by Cl-bridges[Cu_(2.ⅠCl_(2.(Hbcbpy)_(4)]^(4+).BHU-2.as a heterogeneous catalyst exhibits excellent activities to the oxidation desulfurization and photocatalytic hydrogen *** room temperature,BHU-2.can catalyze 96% conversion of methyl phenyl sulfide with 98% selectivity,and the process obeys the pseudo-first-order reaction kinetic with the half-life of9.6 *** notorious 2.chloroethyl ethyl sulfide can achieve 99% conversion with 98% selectivity within only1 min at the presence of BHU-2.and the turnover frequency(TOF) is up to 7400 h^(-1).BHU-2.also exhibits high catalytic activity for the oxidation of other aromatic and aliphatic thioethers within short time at room ***,BHU-2.shows a high catalytic activity for visible-light-driven hydrogen evolution with an H_(2. evolution rate of 1677.85 μmol·g^(-1)·h^(-1) within 10 ***,the catalytic activities do not decrease evidently after three cycles,revealing the prominent structural stability and recyclability.

关键词： Polyoxometalate Metal-organic complex Viologen Oxidation desulfurization Photocatalytic hydrogen production